<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">We have a two story great room in Colorado. I will admit that the climate is mild and sunny here. This means that the hot air goes to the ceiling (20 feet 8 meters or so) during the the day and tries to sink as cold air at night. However, we find that our over sized, slow running Casablanca fan is perfect for setting up total comfort. It will push the air up or down, it is totally quite, comes in a wide variety of classic and contemporary designs (everything from Humphrey Bogart to the Jetsetsons), moves the air slowly without drafts. . <br><div><div>On Feb 4, 2009, at 8:41 PM, Guillaume Jolly wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div> <div><font face="Arial" color="#000000" size="2"> <div id="idOWAReplyText35498" dir="ltr"> <div dir="ltr"><font face="Arial" color="#000000" size="2">Hussein,</font></div> <div dir="ltr"><font face="Arial" size="2">Best practice for building configurations that involve temperature stratification (atriums, high ceiling spaces etc...) is to design them using CFD for load and air distribution. If you regularly come across this configuration, it might be worth it to get a proper CFD study done on it. It must include heat transfer by radiation which become very important as the difference in temperature increase between the house sufaces.</font></div> <div dir="ltr"><font face="Arial" size="2"> </font></div> <div dir="ltr"><font face="Arial" size="2">It will clarify how the air distribution performs in the space, it will show what capacity you need and where you should locate the sensors. By helping to visualise what's happening in the house and comparing it with heat loads calcs, it will give you a feeling for things that you will be able to apply to your next projects. </font> </div> <div dir="ltr"><p class="MsoNormal"><font face="Arial" size="3"><span lang="EN-AU" style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Best Regards</span></font><span lang="EN-AU"></span></p><p class="MsoNormal"><strong><b><i><font face="CityBlueprint" size="5"><span lang="EN-AU" style="FONT-SIZE: 18pt; FONT-STYLE: italic; FONT-FAMILY: CityBlueprint">Guillaume Jolly</span></font></i></b></strong><strong><b><i><font face="CityBlueprint" size="5"><span style="FONT-SIZE: 18pt; FONT-STYLE: italic; FONT-FAMILY: CityBlueprint"></span></font></i></b></strong></p><p class="MsoNormal"><strong><b><font face="Arial Black" size="3"><span lang="EN-AU" style="FONT-SIZE: 12pt; FONT-FAMILY: 'Arial Black'">George Floth Pty. Limited</span></font></b></strong></p><p class="MsoNormal"><strong><b><u><font face="Arial Black" size="1"><span lang="EN-AU" style="FONT-WEIGHT: normal; FONT-SIZE: 8pt; FONT-FAMILY: 'Arial Black'">CONSULTING ENGINEERS</span></font></u></b></strong><strong><b><u><font face="Arial Black" size="1"><span lang="EN-AU" style="FONT-SIZE: 8pt; FONT-FAMILY: 'Arial Black'"> </span></font></u></b></strong><strong><b><i><u><font face="Times New Roman" size="1"><span lang="EN-AU" style="FONT-SIZE: 8pt; FONT-STYLE: italic">BRISBANE</span></font></u></i></b></strong><strong><b><i><u><font face="Times New Roman" size="1"><span lang="EN-AU" style="FONT-SIZE: 8pt; FONT-STYLE: italic"> OFFICE</span></font></u></i></b></strong><b><font face="Arial Narrow" size="1"><span lang="EN-AU" style="FONT-WEIGHT: bold; FONT-SIZE: 8pt; FONT-FAMILY: 'Arial Narrow'"><br></span></font></b><font face="Arial Narrow" color="teal" size="2"><span lang="EN-AU" style="FONT-SIZE: 10pt; COLOR: teal; FONT-FAMILY: 'Arial Narrow'">Ground Floor, 42 Doggett Street<br>Fortitude Valley, Brisbane. 4006</span></font><font face="Arial Narrow" color="teal"><span lang="EN-AU" style="COLOR: teal; FONT-FAMILY: 'Arial Narrow'"><br></span></font><b><font face="Arial Narrow" color="teal" size="2"><span lang="EN-AU" style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: teal; FONT-FAMILY: 'Arial Narrow'">p</span></font></b><font face="Arial Narrow" color="teal" size="2"><span lang="EN-AU" style="FONT-SIZE: 10pt; COLOR: teal; FONT-FAMILY: 'Arial Narrow'"> +61 7 3252 0977<br><b><span style="FONT-WEIGHT: bold">f</span></b> +61 7 3252 2499<br><b><span style="FONT-WEIGHT: bold">e</span></b> <i><span style="FONT-STYLE: italic"><a href="mailto:gjolly@gfbris.com" target="_blank"><font color="teal"><span style="COLOR: teal">gjolly@gfbris.com</span></font></a></span></i></span></font><span lang="EN-AU"></span></p><p class="MsoNormal"><b><font face="Arial Narrow" color="teal" size="2"><span lang="EN-AU" style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; COLOR: teal; FONT-FAMILY: 'Arial Narrow'">w </span></font></b><i><font face="Arial Narrow" color="teal" size="2"><span lang="EN-AU" style="FONT-SIZE: 10pt; COLOR: teal; FONT-STYLE: italic; FONT-FAMILY: 'Arial Narrow'"><a href="https://mail.gfbris.com/exchweb/bin/redir.asp?URL=http://www.gfbris.com/" target="_blank"><font color="teal"><span style="COLOR: teal">www.gfbris.com</span></font></a></span></font></i><span lang="EN-AU"></span></p><br></div> <div dir="ltr"> <hr tabindex="-1"> </div> <div dir="ltr"><font face="Tahoma" size="2"><b>From:</b> Abaza Hussein [<a href="mailto:ahussein@spsu.edu">mailto:ahussein@spsu.edu</a>]<br><b>Sent:</b> Wed 04/02/2009 06:57<br><b>To:</b> <a href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</a><br><b>Subject:</b> [Bldg-sim] Residential System for High Ceiling house<br></font><br></div></div> <div> <div class="Section1"><p class="MsoNormal"><font face="Arial" color="navy" size="2"><span style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Hi all;</span></font></p><p class="MsoNormal"><font face="Arial" color="navy" size="2"><span style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Can any one advice on the best HVAC system configuration for a house with a high ceiling in the great room (other than installing a fan in the ceiling). I have faced this problem many times. The way I was doing it is by over sizing the AC unit for the second floor, and over sizing the furnace for the first floor. But still, the thermostat in the second floor will not help in making the lobby of the first floor much cooler that what it should be. The same thing applies for the heating. Another way I was doing it is by having one system for the entire house and run the fan continuously, but this system is also in efficient, because I can not zone the house. Is there a better way to do it and is there any research in this area?</span></font></p><p class="MsoNormal"><font face="Arial" color="navy" size="2"><span style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Thank you.</span></font></p><p class="MsoNormal"><font face="Arial" color="navy" size="2"><span style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">H. Abaza</span></font></p> <div> <div class="MsoNormal" style="TEXT-ALIGN: center" align="center"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"> <hr tabindex="-1" align="center" width="100%" size="2"> </span></font></div><p class="MsoNormal"><b><font face="Tahoma" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</span></font></b><font face="Tahoma" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> bldg-sim-bounces@lists.onebuilding.org [<a href="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</a>] <b><span style="FONT-WEIGHT: bold">On Behalf Of </span></b>Xiaobing Liu<br><b><span style="FONT-WEIGHT: bold">Sent:</span></b> Tuesday, February 03, 2009 11:41 AM<br><b><span style="FONT-WEIGHT: bold">To:</span></b> 'Bereket Nigusse'; <a href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</a>; Jeff Haberl<br><b><span style="FONT-WEIGHT: bold">Subject:</span></b> Re: [Bldg-sim] Residential System Sizing</span></font></p></div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Bereket:</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">There are many other reasons could explain the differences:</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">1. "System-Sizing-Ratio". For many system, eQUEST uses 1.15 "System-Sizing-Ratio". </span></font></p></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">2. Fan power. Different from space load calc, the system cooling capacity has to account for fan power heat as part of the cooling loads.</span></font></p></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">3. How about latent cooling? Have you accounted for latent cooling in your comparison?</span></font></p></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">4. Make sure the zones in LS-B and SV-A report are exactly the same. Has the loads from roof/ceiling be accounted for in the LS-B report?</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">I am surprised to see in your results that Minneapolis, MN has slightly higher cooling loads (20.3 kBtu/hr in LS-B) than Houston, TX (20.2 kBtu/hr in LS-B).</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Jeff:</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">In your e-mail, you mentioned that "DOE-2 is known for doing a very bad job of sizing for residential". Is there any report/paper detailing this?</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" color="blue" size="2"><span style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Xiaobing</span></font></p></div> <blockquote style="MARGIN-TOP: 5pt; MARGIN-BOTTOM: 5pt"><p class="MsoNormal" style="MARGIN-BOTTOM: 12pt"><font face="Tahoma" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">-----Original Message-----<br><b><span style="FONT-WEIGHT: bold">From:</span></b> bldg-sim-bounces@lists.onebuilding.org [<a href="mailto:bldg-sim-bounces@lists.onebuilding.org">mailto:bldg-sim-bounces@lists.onebuilding.org</a>]<b><span style="FONT-WEIGHT: bold">On Behalf Of </span></b>Bereket Nigusse<br><b><span style="FONT-WEIGHT: bold">Sent:</span></b> Tuesday, February 03, 2009 5:32 AM<br><b><span style="FONT-WEIGHT: bold">To:</span></b> Joe Huang; Ellen Franconi; <a href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</a>; Jeff Haberl<br><b><span style="FONT-WEIGHT: bold">Subject:</span></b> Re: [Bldg-sim] Residential System Sizing</span></font></p> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"><br>Hi All,<br><br>I am modeling a residential building with RESYS as a system, and using auto sizing for system sizing.<br><br>The space temperature (space design temperature) for load calculation is set at 75 oF while the Design-Cool-T is set at 78 oF. I believe that this has the effect of decreasing the system cooling capacity. There is no set-back or set-up applied. No ventilation outdoor air is specified. Infiltration, which is already captured in the building load calculation, is part of the building load. <br><br>How does the system cooling capacity increases by more than 50% (in the case of Minneapolis and Duluth, Minnesota) compared to the building peak load in the absence of any out door air load for ventilation? <br><br>Thanks,<br> <br>Bereket</span></font></p> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div> <div> <div class="MsoNormal" style="TEXT-ALIGN: center" align="center"><font face="Tahoma" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <hr align="center" width="100%" size="1"> </span></font></div><p class="MsoNormal" style="MARGIN-BOTTOM: 12pt"><b><font face="Tahoma" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</span></font></b><font face="Tahoma" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> Joe Huang <<a href="mailto:joe@drawbdl.com">joe@drawbdl.com</a>><br><b><span style="FONT-WEIGHT: bold">To:</span></b> Ellen Franconi <<a href="mailto:EFranconi@archenergy.com">EFranconi@archenergy.com</a>>; <a href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</a>; Jeff Haberl <<a href="mailto:jeffhaberl@tees.tamus.edu">jeffhaberl@tees.tamus.edu</a>>; Bereket Nigusse <<a href="mailto:nigusse_ba@yahoo.com">nigusse_ba@yahoo.com</a>><br><b><span style="FONT-WEIGHT: bold">Sent:</span></b> Tuesday, February 3, 2009 2:16:32 AM<br><b><span style="FONT-WEIGHT: bold">Subject:</span></b> Re: [Bldg-sim] Residential System Sizing</span></font></p> <div><p class="MsoNormal"><font face="Arial" size="3"><span style="FONT-SIZE: 12pt; FONT-FAMILY: Arial">Ellen, </span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" size="3"><span style="FONT-SIZE: 12pt; FONT-FAMILY: Arial">Not exactly. What you wrote is definitely true during the SYSTEMS simulation and peak loads reported in SS-F (?), but Bereket was referring to the SV-A, which is the systems sizing report. Assuming that he's doing "auto-sizing", the DOE-2 sizing routine will take the peak loads from LOADS and compute the design cooling capacity at the COOLING-DESIGN-TEMPERATURE. (I may have the keyword wrong, since I don't have a DOE-2 manual handy). Thus, the termperature discrepancy between the single LOADS temperature and the COOLING-DESIGN-TEMPERATURE does exist, as you've mentioned, but transient loads due to tempeature set-up or set-back or interzone heat flows are not reflected. That's why an autosized SYSTEM will often still result in a few undercooled or underheated hours.</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" size="3"><span style="FONT-SIZE: 12pt; FONT-FAMILY: Arial">My suggestion to Bereket in making sense of the numbers is to compare the TEMPERATURE under SPACE-CONDITIONS for the LOADS reference temperature, to the COOLING-DESIGN-TEMPERATURE (I may have this keyword wrong) is ZONE-CONDITIONS in SYSTEMS. What kind of HVAC are you modeling? It sounds like a residential system (RESYS), but that system doesn't have any OUTSIDE-AIR, does it ? </span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Arial" size="3"><span style="FONT-SIZE: 12pt; FONT-FAMILY: Arial">Joe Huang</span></font></p></div> <div><p class="MsoNormal"><font face="Arial" size="3"><span style="FONT-SIZE: 12pt; FONT-FAMILY: Arial">White Box Technologies, Inc.</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <blockquote style="BORDER-RIGHT: medium none; PADDING-RIGHT: 0in; BORDER-TOP: medium none; PADDING-LEFT: 4pt; PADDING-BOTTOM: 0in; MARGIN: 5pt 0in 5pt 3.75pt; BORDER-LEFT: black 1.5pt solid; PADDING-TOP: 0in; BORDER-BOTTOM: medium none"> <div style="font-size-adjust: none; font-stretch: normal"><p class="MsoNormal"><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">----- Original Message ----- </span></font></p></div> <div style="font-size-adjust: none; font-stretch: normal"><p class="MsoNormal" style="BACKGROUND: #e4e4e4"><b><font face="Arial" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">From:</span></font></b><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <a title="EFranconi@archenergy.com" href="mailto:EFranconi@archenergy.com" target="_blank">Ellen Franconi</a> </span></font></p></div> <div style="font-size-adjust: none; font-stretch: normal"><p class="MsoNormal"><b><font face="Arial" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">To:</span></font></b><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <a title="bldg-sim@lists.onebuilding.org" href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a> ; <a title="jeffhaberl@tees.tamus.edu" href="mailto:jeffhaberl@tees.tamus.edu" target="_blank">Jeff Haberl</a> ; <a title="nigusse_ba@yahoo.com" href="mailto:nigusse_ba@yahoo.com" target="_blank">Bereket Nigusse</a> </span></font></p></div> <div style="font-size-adjust: none; font-stretch: normal"><p class="MsoNormal"><b><font face="Arial" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">Sent:</span></font></b><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> Monday, February 02, 2009 7:50 PM</span></font></p></div> <div style="font-size-adjust: none; font-stretch: normal"><p class="MsoNormal"><b><font face="Arial" size="2"><span style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Arial">Subject:</span></font></b><font face="Arial" size="2"><span style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> Re: [Bldg-sim] Residential System Sizing</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Another reason that the results are different is that the space temperature may be different in the "loads" part of the DOE-2 program than in the "systems" part of the program. In "loads", the space temperatures are set equal to the space design temperate. In "systems", the space temperature is based on the zone setpoint schedule and whatever temperature is actually achieved in the space. Thus, if you have a set up or a setback from the design space temperature, it will be different. </span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Ellen</span></font></p></div> <div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></div> <div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Ellen Franconi, Ph.D., LEED AP</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Energy Analysis Group Manager</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Architectural Energy Corporation</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">2540 Frontier Avenue</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">Boulder</span></font>, CO 80301</p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">tel. 303-444-4149</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">fax 303-444-4303</span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"><a href="mailto:efranconi@archenergy.com" target="_blank">efranconi@archenergy.com</a></span></font></p></div> <div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"><a href="http://www.archenergy.com/" target="_blank">http://www.archenergy.com/</a></span></font></p></div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"><br><br>>>> Jeff Haberl <<a href="mailto:jeffhaberl@tees.tamus.edu">jeffhaberl@tees.tamus.edu</a>> 2/2/2009 8:40 PM >>><br>Bereket:<br><br>I would not expect the values in SV-A and LS-B to agree for most buildings. There are many reasons for this.<br><br>First, peak loads from LOADS do not include ventilation loads as would be the case in SYSTEMS, only infiltration. <br>Second, you may be looking at different days on the weather file between LOADS and SYSTEMS, so this would <br>need to be checked. <br><br>In addition, DOE-2 sizes for the absolute peak, whereas other methods, such as Manual J, have some undersizing<br>built into the procedures, hence you'll almost always get a much larger system size in DOE-2. <br><br>Both the SV-A and LS-B lists you show seem reasonable, with the exception of the MN #s, which I suspect that you<br>may have a fair bit of 24 hour infiltration in your input file...(i.e., low night time temps in MN?) <br>However, without looking at the file I can only guess. <br><br>There are 100s of reasons for the funny little differences you show. You're probabloy better off running a Manual J <br>calculation on the house if it is residential. DOE-2 is known for doing a very bad job of sizing for residential.<br><br>Jeff<br><br>8=! 8=) :=) 8=) ;=) 8=) 8=( 8=) :=') 8=) 8=) 8=?<br>Jeff S. Haberl, Ph.D., P.E.............................<a href="mailto:jhaberl@esl.tamu.edu">jhaberl@esl.tamu.edu</a><br>Professor......................................................Office Ph: 979-845-6507<br>Department of Architecture.......................Lab Ph: 979-845-6065 <br>Energy Systems Laboratory.......................FAX: 979-862-2457 <br>Texas A&M University..............................77843-3581<br>College Station, Texas, USA.......................URL: <a href="http://www-esl.tamu.edu/" target="_blank">www-esl.tamu.edu</a><br>8=/ 8=) :=) 8=) ;=) 8=) 8=() 8=) 8=? 8=) 8=) 8=) <br><br>________________________________<br><br>From: <a href="mailto:bldg-sim-bounces@lists.onebuilding.org">bldg-sim-bounces@lists.onebuilding.org</a> on behalf of Bereket Nigusse<br>Sent: Mon 2/2/2009 5:59 PM<br>To: <a href="mailto:bldg-sim@lists.onebuilding.org">bldg-sim@lists.onebuilding.org</a><br>Subject: [Bldg-sim] Residential System Sizing<br><br><br><br>Hello All,<br><br>I have a problem with DOE2.1E cooling system sizing. The cooling capacity reported by DOE2.1e in SV-A and LS-B reports are quite different and shows different sensitivity trends depending locations. <br><br>Question 1<br>For the case with out door air flow ratio input set to zero DOE2.1E calculated cooling capacity and the peak coolig load are shown below. I assume that the out door air contribution to the system load is zero for zero out door air fraction and with this assumption the system cooling capacity will be different from the peak cooling load only due to difference in ARI and the peak cooling load hour weather conditions. What else could cause the cooling capacity to be different from the peak load for zero out door air flow rate case? I have looked into to DOE2.1E manual but wasn't able connect the steps from the peak cooling load to the system capacity? <br><br>Question 2<br>Does the change from the peak cooling load to the system cooling capacity seem a reasonable for the different loacations given below? <br>The building is 2100 sqft conditioned floor area, two story, single family house. Each floor is modeled as a single zone.<br><br><br> Report AV-A Report LS-B <br>Locations Supply Flow, CFM Cooling Capacity, kBtu/hr Peak Cooling Load, kBtu/hr Outdoor DB Temp at Peak Load, oF Outdoor WB Temp at Peak Load, oF<br>Baltimore, MD 850.0 25.7 22.1 93 73<br>Houston, TX 813.0 27.0 20.2 93 78<br>Chicago, IL 1054.0 29.3 20.3 89 72<br>Minneapolis, MN 1226.0 33.5 20.3 89 79<br>Duluth, MN 1258.0 34.8 18.1 87 72<br>Phoenix, AZ 1281.0 37.4 31.6 114 71<br><br><br>Thank you in advance for the help,<br><br><br>Bereket<br><br>_______________________________________________<br>Bldg-sim mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/bldg" target="_blank">http://lists.onebuilding.org/listinfo.cgi/bldg</a>-sim-onebuilding.org<br>To unsubscribe from this mailing list send a blank message to <a href="mailto:BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG">BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG</a></span></font></p></div> <div class="MsoNormal" style="TEXT-ALIGN: center" align="center"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"> <hr align="center" width="100%" size="2"> </span></font></div><p class="MsoNormal"><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt">_______________________________________________<br>Bldg-sim mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org" target="_blank">http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>To unsubscribe from this mailing list send a blank message to <a href="mailto:BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG">BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG</a></span></font></p></blockquote></div></div></div><div><font face="Times New Roman" size="3"><span style="FONT-SIZE: 12pt"></span></font> <br class="webkit-block-placeholder"></div></blockquote></div></div></font></div></div>_______________________________________________<br>Bldg-sim mailing list<br><a href="http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org</a><br>To unsubscribe from this mailing list send a blank message to BLDG-SIM-UNSUBSCRIBE@ONEBUILDING.ORG<br></blockquote></div><br></body></html>